FINIS Tempo Trainer Pro Personal pace coach with 3 different modes. Waterproof device transmits an audible tempo beep to eliminate lulls in workouts and races. Tempo is adjustable by 1/100th of a second, giving you the ability to identify and maintain your ideal pace. The dryland clip allows it to be used for multiple sports, in and out of the water (swim, bike, golf, run & more). Replaceable battery extends the life. Waterproof- Tested to perform at a depth of 10 meters